- Oct 1 Héctor Campos Parsi, Puerto Rican classical music composer, born in Ponce, Puerto Rico (d. 1997)
- Oct 1 James Whitmore, American actor (The Shawshank Redemption, Give 'em Hell Harry), born in White Plains, New York (d. 2009)
- Oct 2 Albert Scott Crossfield, American test pilot (XS-1), born in Berkeley, California (d. 2006)
- Oct 2 Robert Runcie, Archbishop of Canterbury, born in Liverpool, England (d. 2000)
- Oct 3 Ray Lindwall, Australian cricket fast bowler (61 Tests, 228 wickets @ 23.03), born in Sydney, Australia (d. 1996)
- Oct 4 Shin Kyuk-Ho, Korean businessman (Lotte Corporation), born in Ulsan, Korea (d. 2020)
- Oct 5 Bill Willis, American College-Pro Football HOF defensive tackle (NFL C'ship 1950; 4 × First-team All-Pro; 3 × Pro Bowl; Cleveland Browns), born in Columbus, Ohio (d. 2007)
- Oct 6 Evgenii Landis, Soviet Russian mathematician, born in Kharkiv, Ukrainian SSR, Soviet Union (d. 1997)
- Oct 7 John Arthur Giles Gere, English art historian (Pre-Raphaelite painter)
- Oct 8 Abraham Sarmiento, Sr., Filipino Supreme Court jurist (1987-91), born in Santa Cruz, Ilocos Sur, Philippine (d. 2010)
- Oct 9 Dot Wilkinson, American pro bowler (WIBC Queen's Tournament 1962, WIBC singles title 1963) and softball player (19 x All American), born in Phoenix, Arizona (d. 2023)
- Oct 9 Michel Boisrond, French film director and screenwriter, born in Châteauneuf-en-Thymerais, France (d. 2002)
- Oct 10 Boy Trip, Dutch minister, born in Amersfoort, Netherlands (d. 1990)
Jaroslav Drobný (1921-2001)
Oct 12 Czech ice hockey player (Olympic silver 1948) and tennis player (Wimbledon 1954, French Open 1951-52), born in Prague, Czech Republic
- Oct 12 Les Horvath, American College Football Hall of Fame quarterback and halfback (Heisman Trophy 1944; first Ohio State player to win the award; National C'ship 1942), born in South Bend, Indiana (d. 1995)
- Oct 13 Harper MacKay, American orchestra leader (NBC Follies), born in Boston, Massachusetts (d. 1995)
- Oct 13 Yves Montand [Ivo Livi], Italian-French actor and singer (Z, Napoleon, Grand Prix), born in Monsummano Terme, Italy (d. 1991)
- Oct 15 Angelica Rozeanu, Romanian table tennis player (World Champ 1950-55), born in Bucharest, Romania (d. 2006)
- Oct 15 Gul Mahomed, Pakistani cricketer (Indian & Pakistani batsman), born in Lahore, Punjab, British India (d. 1992)
- Oct 16 Matt Batts, MLB catcher (Red Sox), born in San Antonio, Texas (d. 2013)
- Oct 16 Michael Conrad, American Emmy Award-winning actor (Hill Street Blues - "Sgt. Phil Esterhaus"), born in NYC, New York (d. 1983)
- Oct 17 George Mackey Brown, poet
- Oct 17 Maria Gorokhovskaya, Russian gymnast (equal record 7 x Olympic medals, Soviet Union 1952; 2 x gold [team, all-round], 5 x silver), born in Yevpatoria, Russia (d. 2001)
- Oct 17 Pricilla Lanford Buckly, editor/columnist (National Review)
- Oct 17 Tom Poston, American actor (Newhart, Mork & Mindy, Steve Allen Show, Newhart), born in Columbus, Ohio (d. 2007)
- Oct 18 Jesse Helms, American politician (Senator -D/R-North Carolina, 1973-2003), born in Monroe, North Carolina (d. 2008)
- Oct 19 George Nader, American actor (Robot Monster, Away All Boats), born in Pasadena, California (d. 2002)
- Oct 19 Gunnar Nordahl, Swedish soccer striker (33 caps; AC Milan; Olympic gold 1948), born in Hörnefors, Sweden (d. 1995)
- Oct 20 Hans Warren, Dutch writer, poet and critic (Secret Diary)
- Oct 20 Pierre Laporte, Canadian journalist and statesman (Revolution Script)
- Oct 21 Jarmil Burghauser, composer
- Oct 21 Sir Malcolm Arnold, British trumpeter, and classical and film score composer (The Bridge On The River Kwai), born in Northampton, England (d. 2006)
- Oct 22 Alexander Kronrod, Russian mathematician (d. 1986)
- Oct 22 Georges Brassens, French poet/cabaret singer
- Oct 23 Denise Duval, French soprano (music of Francis Poulenc), born in Paris (d. 2016)
- Oct 23 İlhan Usmanbaş, Turkish contemporary classical composer, born in Constantinople (now İstanbul), Turkey
- Oct 23 Tom Manders, Dutch cabaret artist (Dorus)
- Oct 25 Brian Malzard Foss, British psychologist, born in Whittlesey, Cambridgeshire (d. 1997)
- Oct 25 Michael I, King of Romania (1927-30, 1940-47), born in Peleș Castle, Sinaia, Romania (d. 2017)
- Oct 26 George Forrest, Northern Irish politician (d. 1968)
- Oct 27 Anestis Logothetis, Austrian composer, born in Burgas, Bulgaria (d. 1994)
- Oct 27 Warren Allen Smith, American gay rights activist and writer, born in Minburn, Iowa (d. 2017)
- Oct 28 Arturo "Chico" O'Farrill, Cuban Latin and Afro-Cuban jazz composer, arranger, and conductor, born in Havana, Cuba (d. 2001)
- Oct 28 Peggy Kirk, American golfer, (Titleholders Championship 1949), born in Findlay, Ohio (d. 2016)
- Oct 29 Bill Mauldin, American cartoonist famous for his World War II cartoons depicting American soldiers (Pulitzer-1945, 59), born in Mountain Park, New Mexico (d. 2003)
- Oct 29 Edward "Ed" Kemmer, American actor (Space Patrol, Lux Video Theatre), born in Reading, Pennsylvania (d. 2004)
About October 1921
How Old? 101 years old
Generation: Greatest Generation
Leap Year: No